Facebook founder and CEO Mark Zuckerberg announced Thursday that his company has reached an unprecedented milestone: one billion users.

In an exclusive interview with NBC’s Matt Lauer, Zuckerberg said the 8-year-old company added 200 million new users in the last year and called having a billion users across the world “an amazing honor.”

“To be able to come into work every day and build things that help a billion people stay connected with the people they care about every month, that’s just unbelievable,” Zuckerberg said in an interview airing Thursday morning on Today and on NBC’s Rock Center with Brian Williams at 10pm/9c.

Despite the excitement of crossing the billion mark, Zuckerberg acknowledged the company’s leadership and its staff have been in a “tough cycle” in the months since the company’s initial public offering in May.

Valued at $100 billion when it went public, Facebook is now worth nearly half that. The social network has faced new scrutiny from its users and investors over how it plans to make money from those billion users, especially the ones who access Facebook through mobile devices.

“Things go in cycles. We’re obviously in a tough cycle now and that doesn’t help morale, but at the same time, you know, people here are focused on the things that they’re building,” said Zuckerberg of his staff. “I mean, you get to build things here that touch a billion people, which is just not something that you can say at almost anywhere else, so I think that’s really the thing that motivates people.”

The drop in the company’s value has left many questioning if the 28-year-old tech visionary has the business know-how to be CEO.

“I take this responsibility that I have really seriously and I really think Facebook needs to be focused on building the best experiences for people around the world, right? And we have this philosophy that building the products and services and building the business go hand in hand,” Zuckerberg said.

Zuckerberg said that he and his team are focusing on growing the number of people who use Facebook on mobile devices, such as smartphones, a move that he says will make money and respond to the changing needs of their users.

“There’s five billion people in the world who have phones, so we should be able to serve many more people and grow the user base there,” Zuckerberg said.

Of his strategy as CEO, Zuckerberg said that he has taken a few lessons from his late friend, Apple founder Steve Jobs.

“I mean, he was just so focused, right? I mean for him, the user experience was the main thing that mattered, the only thing that mattered and I think that there’s a lot that every company can learn from that,” he said. “We’ve had a lot of that philosophy too, which is we just want to stay maniacally focused on building the best product for those people and I think that’s the path to building a great business and, you know, I think that’s something that Steve understood more than most.”

Zuckerberg is also friends with current Apple CEO Tim Cook who recently gave him a new iPhone 5 as a gift. Zuckerberg, who called the phone a “wonderful device,” wouldn’t say which mobile device he thinks is the best. More people use Facebook on Android than on the iPhone, Zuckerberg said.

“It’s a pretty diverse ecosystem and we spend our time building for all these different things,” he said.

Zuckerberg’s army of builders work on the company’s sprawling campus headquarters in Menlo, Park, Calif. The word “hack” is imprinted on one of the walkways; a homage to the spirit with which Zuckerberg founded the social network. In a building with a red sign saying, “The Hacker Company,” casually clad programmers, engineers and designers toil for the CEO they call 'Mark.'

Zuckerberg, often wearing a uniform of jeans and a gray t-shirt, said he frequently leaves his glass office in the afternoons to roam the offices or walk outdoors to talk to his staff. Every Friday, Zuckerberg holds a weekly Q&A for team members to air their grievances and propose their ideas.

Zuckerberg said he tries to keep his personal life “simple.” When his May wedding to Priscilla Chan was splashed across magazine covers, he said it felt “odd.”

“It’s surprising, but you know, it doesn’t take away from these moments, right? I mean the wedding was an awesome thing,” he said.

Zuckerberg met Chan when both were students at Harvard. He said they secretly planned their wedding to be around the time Chan finished medical school.

“I sent out this email to all our friends, telling them that I was having a surprise party for her from graduating from medical school,” he said. “It was a really small wedding. We had it in our backyard. It was 80 or so people, but it was really nice.”

Of his future, Zuckerberg said his company’s mission has morphed into his life’s mission.

“Our responsibility as a company is just to do the best that we can and build the best products for people,”Zuckerberg said.“If we build the best products, then I think that we can continue leading in this space for a long time.”